Various services can be provided for a user of a user equipment by means of a telecommunication system. Services that utilise information about the geographical location of a user in the service provisioning i.e. the so called location sensitive services are also known. Recent development in the field of mobile user equipment such as mobile telephones and other mobile stations has lead to arrangements wherein information about the current location of the mobile user equipment is determined and utilised in provision services for the mobile users.
A well known example of the communication systems providing mobility for the users is the public land line mobile network (PLMN), a cellular communication network being an example of the PLMN. Another example is a mobile communication system that is based, at least partially, on use of communication satellites. The skilled person is aware of the basic principles of a such communication systems. A mobile communication system typically operates in accordance with a given standard or specification which sets out what the various elements of the system are permitted to do and how that should be achieved. For example, the standard or specification may define if the user, or more precisely, user equipment or terminal is provided with a circuit switched service or a packet switched service or both. Communication protocols and/or parameters which shall be used for the connection are also typically defined. For example, the manner how communication shall be implemented between the user equipment and the elements of the communication network is typically based on a predefined communication protocol. In other words, a specific set of “rules” on which the communication can be based on needs to be defined to enable communication by means of the communication system.
A communication system needs to be able to provide various different functions in order be able to operate. These functions can be divided in different categories. A category comprises functions that relate to the actual carrying of the communication such as voice or multimedia or other data content in the system. Another category can be seen as being formed by control or management functions such as the control of various services and the actual communication. Signalling of messages associated with different functions is thus understood as being implemented on different planes. For example, control messages are communicated on a control plane and the actual communication is then transported on a user plane. The communication on the user plane is supported the signalling of the control messages on the control plane.
Typically the communication systems provide this by means of separate channels, e.g. by means of separated signalling and communication channels. Such arrangements are employed e.g. by signalling system 7 (SS7) core networks and Q.931/GSM/WCDMA subscriber access. Therefore the term “Signalling channel” may be used when referring to control plane communications. Similarly the term communication channel may be used when referring to user plane communications.
The various functions of the communication systems may have been developed quite independently from each other and may use different protocols in different communication systems. The standards and protocols define e.g. which plane shall be used for a certain purpose.
The mobile network apparatus and/or user equipment such as a mobile station can be employed for provision of information regarding the geographical location of the user equipment and thus the user thereof. A mobile user equipment and thus the user thereof can be positioned by various different techniques. For example, substantially accurate geographical location information that associates with a user equipment can be obtained based on the known satellite based GPS (Global Positioning System). More accurate location information can be obtained through a differential GPS. In another approach the cells or similar geographically limited radio access entities and associated controllers of the communication system are utilised in production of an estimate concerning the location of the mobile user equipment. To improve the accuracy of the location information the communication system may be provided with specific location measurement units (LMUs) that provide more accurate data or additional data concerning the location of a user equipment. It is also possible to conclude geographical location when the mobile user equipment is located within the coverage area of a visited or “foreign” network. The visited network may be made capable of transmitting the location of the mobile user equipment back to the home network, e.g. to support services that are based on location information or for the purposes of routing and charging. The production of data for the location determinations (such as various measurements and calculations) does not form an essential element of the present invention, and is thus not described in any greater detail herein.
A location service (LCS) entity may be employed in the provisioning of location information associated with a target user equipment for entities who have requested for such information (the clients). The LCS client may make use of that location information for various services/applications. The location service entity may implemented within the cellular system or connected thereto. The location service entity provided by the communication system may serve different clients via an appropriate interface.
Location data may be provided to the location service entity from various sources connected to the communication system. Location data may also be processed in the user equipment that is provided with appropriate processing capacity. The user equipment may then provide the location service entity or the client with processed data such as location co-ordinates.
The location information may be used for various purposes, such as for location of a mobile telephone that has made an emergency call, for locating vehicles or given mobile subscribers for commercial purposes and so on. In general, a client such as a user or entity wishing to receive location information regarding another user may send a request for such information to the location service provision entity. The location service provisioning entity will then process the request, obtain the required data and generate an appropriate response.
An example of the provision of the location information by a PLMN is described in more detail 3rd Generation Partnership Project (3GPP) technical specifications, see e.g. 3GPP TS 23.271 version 4.2.0, titled “Functional stage 2 description of LCS”, June 2001.
According to the 3GPP specification a location service (LCS) server entity referred to as a Gateway Mobile Location Center (GMLC) is provided for managing the location services. The GMLC is for gathering and storing various data that may be used in provision of location information for the location service clients (LCS clients). The present location service (LCS) solutions employ control plane signalling channels for signalling messages that associate with the provisioning of the location services, such as for requests for location information, messages for conveying LCS assistance data and so on.
However, the inventors have found that the signalling of messages that associate with the provisioning of the location information may cause relatively high load on the control plane. This may be especially the case in the air interface between the mobile user equipment and the radio network servicing the mobile user equipment.
A further problem may arise in situations wherein by the communication system does not support provision of location information services or supports only certain types of services. In the prior art communication systems all elements in a LCS chain may need to support the provision of the location services. For example, involvement of all associated entities such as the GMLC (Gateway Mobile Location Center), HLR (Home Location Register), MSC/SGSN(s) (Mobile Switching Center/Serving GPRS Support Node) and other controllers is required. Support by the base station(s) and/or the user equipment may also be required.
This may be the case e.g. when new telecommunication standards or new type of services are introduced. A new communication system may be initially run based on substantially basic protocols and so on, are therefore may not be able to support any more “sophisticated services”. For example, the recently launched GPRS (General Packet Radio Service) networks do not support provision of location information services for packet switched data communication sessions. A solution that overcomes also this problem might thus be appreciated by the service providers and users of the telecommunication system.